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Good Housekeeping Output Tube Bias
Your new REACTOR 112 has an internally mounted variable bias control. The bias control is
used to set the idle current in the output tubes, properly matching amp’s performance
characteristics to the type of tubes used. Each different tube brand and manufacturer may
require a slightly different bias setting. An amp’ s bias can drift over time as well as the tubes
bias requirements may change with extended use. The bias should be checked periodically and
when the tubes are replaced. A properly biased amp will sound great and will run reliably and
safely.
Beware! Internal voltages of tube type amplifiers are lethal and capacitors are capable of storing
these lethal charges. To ensure tone and safety, qualified personnel only should carry out
biasing the amp.
Tube Replacement
The REACTOR 112 tube compliment consists in one 12AX7 used as a phase inverter (not a pre-
amp) and two EL-84s for power. For continued optimum performance from your REACTOR 112,
these tubes should only be replaced with tubes of the same type and specification.
The Fuse
The fuse is in the AC supply of the amplifier and will help to protect the amplifier in the event of
an electrical fault or tube failure. If a fuse blows, replace it only with one of the same type and
rating. (Refer to the specification page to determine the correct fuse type and rating.) NEVER
use a fuse with a higher rating as this could damage the amp and present a serious safety
hazard. If the fuse blows repeatedly, the amp should be taken to an authorized service center.
Always Use High Quality Shielded Cables.
The Reactor 112 loves to be fed really good signals so now might be a good time to make sure
your not cheating yourself out of any sound quality. Some cable companies are all hype but
some can provide an amazing improvement. Take some time and “listen to your cables” a few
bucks on a good instrument cable can go a long way toward getting the sound you are looking
for.